In facilities of this type, the axial bearing usually has a large diameter since it is arranged close to or on the edge of the shaft, and in the form of one or more axially superimposed rings around the pipes. The shaft may effectively be of large diameter when it is required to pass through the turret a large number of fluid-transfer pipes. However, the manufacture of bearings of suitably large diameter is complicated, and, in addition, consideration must be given at the designing stage to major structural deformations, subsidence, or out-of-round deformation. The manufacture of bearing and carrier structure assemblies therefore proves to be difficult, and the preparation of bearing raceways in particular to obtain the required planarity and their installation entail numerous constraints.